Automatic water replenishing device of waste heat boiler

Abstract

The utility model discloses an automatic water replenishing device of a waste heat boiler, which comprises a softener, a water storage unit, a feed pump and a boiler which are sequentially connected, a stop valve is arranged between the water inlet end of the water storage unit and the water outlet end of the softener, the water outlet end of the water storage unit is connected with the water inlet end of the feed pump, and the water outlet end of the water pump is connected with the water inlet end of the boiler. The water storage unit comprises a main softened water storage tank and a secondary softened water storage tank which are arranged in parallel, a first electromagnetic valve and a third electromagnetic valve are respectively arranged at the water inlet end and the water outlet end of the main softened water storage tank, and a second electromagnetic valve and a fourth electromagnetic valve are respectively arranged at the water inlet end and the water outlet end of the secondary softened water storage tank; a first liquid level sensor and a second liquid level sensor are respectively arranged on the main softened water storage tank and the secondary softened water storage tank, and a pressure sensor is arranged on the boiler. The water storage unit is additionally arranged between the water softener and the boiler, so that the operation stability of the boiler system is improved, the defect that the cost is increased due to the fact that a plurality of water softeners are additionally arranged is overcome, and the practicability is good.

Description

Technical Field

[0001] The utility model relates to the technical field of boiler water replenishment, in particular to an automatic water replenishment device for a waste heat boiler. Background Art

[0002] Our plant's flue gas waste heat power generation boiler system currently consists of three waste heat boilers operating in parallel. Each waste heat boiler has a rated evaporation capacity of 25 t / h. Two are in normal operation, with one serving as a standby. Due to the unstable and wide fluctuations in the flue gas temperature of the submerged arc furnace, the boiler evaporation capacity fluctuates significantly. When the submerged arc furnace operates normally, the flue gas temperature is around 600°C, and the evaporation capacity of the waste heat boiler is 25 t / h. When the submerged arc furnace is unstable, the flue gas temperature can reach over 700°C, and the evaporation capacity of the waste heat boiler can reach over 30 t / h. In this case, the sudden increase in the submerged arc furnace flue gas temperature and the sudden increase in the boiler evaporation capacity necessitates increasing the feedwater flow to over 45 t / h. Combined with the feedwater flow from the other operating boiler, the total feedwater requirement is approximately 75 t / h. Due to the limitations of the boiler's pre-water softener, when the feedwater flow reaches 60 t / h, the softener will overload and vibrate, causing the softener to malfunction and halt boiler water replenishment. Insufficient boiler water supply will lead to water shortage accidents, requiring emergency shutdown of the boiler. In severe cases, it may cause boiler tube bursts, affecting the safe operation of the boiler. Utility Model Content

[0003] The purpose of the utility model is to provide an automatic water replenishing device for a waste heat boiler to solve the problems existing in the above-mentioned background technology.

[0004] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0005] A waste heat boiler automatic water replenishment device includes a softener, a water storage unit, a water feed pump and a boiler connected in sequence, a stop valve is provided between the water inlet end of the water storage unit and the water outlet end of the softener, the water outlet end of the water storage unit is connected to the water inlet end of the water feed pump, and the water outlet end of the water feed pump is connected to the water inlet end of the boiler, the water storage unit includes a main softened water storage tank and a secondary softened water storage tank arranged in parallel, the water inlet end and the water outlet end of the main softened water storage tank are respectively provided with a first solenoid valve and a third solenoid valve, and the water inlet end and the water outlet end of the secondary softened water storage tank are respectively provided with a second solenoid valve and a fourth solenoid valve; the main softened water storage tank and the secondary softened water storage tank are respectively provided with a first liquid level sensor and a second liquid level sensor, and the boiler is provided with a pressure sensor.

[0006] It also includes a PLC controller, which is respectively connected to the first solenoid valve, the second solenoid valve, the third solenoid valve, the fourth solenoid valve, the first liquid level sensor, the water supply pump, the second liquid level sensor and the pressure sensor signals.

[0007] Compared with the prior art, the present invention has the following beneficial effects:

[0008] The utility model improves the operating stability of the boiler system by adding a water storage unit between the water softener and the boiler, avoids the disadvantage of increased cost caused by adding multiple water softeners, and two softened water storage tanks are used as a backup, and water supply can be started at the same time in an emergency, thereby improving the safety redundancy of the boiler system operation and having good practicality. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a structural diagram of the present utility model.

[0010] In the figure, 1-stop valve, 2-first solenoid valve, 3-second solenoid valve, 4-primary softened water storage tank, 5-secondary softened water storage tank, 6-first liquid level sensor, 7-third solenoid valve, 8-fourth solenoid valve, 9-water feed pump, 10-second liquid level sensor, 11-boiler, 12-pressure sensor. DETAILED DESCRIPTION

[0011] The present invention will be further explained below with reference to the accompanying drawings.

[0012] like Figure 1 As shown, an automatic water replenishment device for a waste heat boiler includes a softener, a water storage unit, a water feed pump 9 and a boiler 11 connected in sequence, a stop valve 1 is provided between the water inlet end of the water storage unit and the water outlet end of the softener, the water outlet end of the water storage unit is connected to the water inlet end of the water feed pump 9, the water outlet end of the water feed pump 9 is connected to the water inlet end of the boiler 11, and a check valve 13 is provided between the water feed pump 9 and the boiler 11. The water storage unit includes a main softened water storage tank 4 and a secondary softened water storage tank 5 arranged in parallel, and the volume of the main softened water storage tank 4 is 1 to 2 times the volume of the secondary softened water storage tank 5. The water inlet and water outlet of the main softened water storage tank 4 are respectively provided with a first solenoid valve 2 and a third solenoid valve 7, and the water inlet and water outlet of the secondary softened water storage tank 5 are respectively provided with a second solenoid valve 3 and a fourth solenoid valve 8; in addition, the main softened water storage tank 4 and the secondary softened water storage tank 5 are respectively provided with a first liquid level sensor 6 and a second liquid level sensor 10, and the boiler 11 is provided with a pressure sensor 12.

[0013] In order to realize automatic water replenishment, the utility model also includes a PLC controller (not shown in the figure), which is respectively connected to the first solenoid valve 2, the second solenoid valve 3, the third solenoid valve 7, the fourth solenoid valve 8, the first liquid level sensor 6, the water supply pump 9, the second liquid level sensor 10 and the pressure sensor 12 for signal connection.

[0014] In addition, a cleaning water pipe and a sewage pipe are respectively provided at the bottom of the main softened water storage tank 4 and the secondary softened water storage tank 5 for inspecting and cleaning the softened water storage tanks.

[0015] The specific working process of this utility model is as follows:

[0016] When the boiler is operating normally, i.e., the evaporation rate remains normal and the pressure data fed back by pressure sensor 12 is within the normal range, stop valve 1, first solenoid valve 2, second solenoid valve 3, and third solenoid valve 7 are open, while fourth solenoid valve 8 is closed. This means that boiler water replenishment is maintained only by the primary softened water storage tank 4, while water is stored in the secondary softened water storage tank 5. The PLC controller controls the intermittent activation of the feedwater pump 9 via a time relay. Check valve 13 prevents backflow of feedwater when the feedwater pump 9 stops operating. The openings of the first solenoid valve 2 and the second solenoid valve 3 are controlled by the PLC controller to ensure that the majority of the softened water enters the primary softened water storage tank 4, while a smaller portion enters the secondary softened water storage tank 5 for storage. Valve openings are adjusted based on the liquid level data fed back by the first and second liquid level sensors 6 and 10 to ensure that the water level in the primary softened water storage tank 4 remains within the process-permitted range. At the same time, when the second liquid level sensor 10 feeds back that the liquid level in the secondary softened water storage tank 5 reaches the high water level line, the second solenoid valve 3 is closed.

[0017] When the boiler is in an abnormal state, that is, the evaporation volume is huge, and the pressure data fed back by the pressure sensor 12 deviates from the normal range, the stop valve 1, the first solenoid valve 2, the second solenoid valve 3, the third solenoid valve 7 and the fourth solenoid valve 8 are opened at the same time, and the PLC controller skips the time relay (or modifies the time interval to 0) and directly controls the water supply pump 9 to replenish water urgently to avoid boiler failure shutdown.

[0018] In summary, the utility model improves the operating stability of the boiler system by adding a water storage unit between the water softener and the boiler, avoids the disadvantage of increased costs caused by adding multiple water softeners, and two softened water storage tanks are used as a backup, and water supply can be started at the same time in an emergency, thereby improving the safety redundancy of the boiler system operation and having good practicality.

Claims

1. An automatic water replenishment device for a waste heat boiler, comprising a softener, a water storage unit, a water feed pump (9) and a boiler (11) connected in sequence, a stop valve (1) being provided between the water inlet of the water storage unit and the water outlet of the softener, the water outlet of the water storage unit being connected to the water inlet of the water feed pump (9), and the water outlet of the water feed pump (9) being connected to the water inlet of the boiler (11), characterized in that: The water storage unit comprises a main softened water storage tank (4) and a secondary softened water storage tank (5) arranged in parallel, wherein the water inlet end and the water outlet end of the main softened water storage tank (4) are respectively provided with a first solenoid valve (2) and a third solenoid valve (7), and the water inlet end and the water outlet end of the secondary softened water storage tank (5) are respectively provided with a second solenoid valve (3) and a fourth solenoid valve (8); the main softened water storage tank (4) and the secondary softened water storage tank (5) are respectively provided with a first liquid level sensor (6) and a second liquid level sensor (10), and the boiler (11) is provided with a pressure sensor (12).

2. The automatic water replenishing device for waste heat boiler according to claim 1, characterized in that: The system further comprises a PLC controller, wherein the PLC controller is respectively connected to the first solenoid valve (2), the second solenoid valve (3), the third solenoid valve (7), the fourth solenoid valve (8), the first liquid level sensor (6), the water supply pump (9), the second liquid level sensor (10) and the pressure sensor (12) for signal communication.

3. The automatic water replenishing device for a waste heat boiler according to claim 1, characterized in that: A check valve (13) is provided between the water feed pump (9) and the boiler (11).

4. The automatic water replenishing device for a waste heat boiler according to claim 1, characterized in that: The volume of the primary softened water storage tank (4) is 1 to 2 times the volume of the secondary softened water storage tank (5).

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